What the hell is wrong with this transaction...

yakuza699

hero member

Activity: 935

Merit: 1002

Quote from: shorena on December 06, 2014, 08:17:59 AM

I wouldnt call it an exploit. As long as someone along the chain does not accept zero confirmation transactions the "attack" fails. And you should not accept transactions without confirmations for several reasons anyway.

It is really hard for an attacker to send a big chain of transactions spending each other and using 0 as a fee as most of the bitcoin nodes will simply not relay those transactions as there are many anti-ddos mechanisms on bitcoin core clients.

To op. Does your shop accepts 0 confirmation transactions?

cr1776

legendary

Activity: 4130

Merit: 1307

Quote from: tarashy on December 06, 2014, 08:22:08 AM

Quote from: shorena on December 06, 2014, 08:17:59 AM

And you should not accept transactions without confirmations for several reasons anyway.

As far as I know, I cant choose when using Blockchain's API.....

That would be something to discuss with blockchain.info then, use someone else's API, or run your own Bitcoin core. If you can't choose that when using the bc.i API this is the type of situation they should help protect against.

This seems off-topic for this section by the way.

tarashy

newbie

Activity: 6

Merit: 0

Quote from: shorena on December 06, 2014, 08:17:59 AM

And you should not accept transactions without confirmations for several reasons anyway.

As far as I know, I cant choose when using Blockchain's API.....

shorena

copper member

Activity: 1498

Merit: 1528

No I dont escrow anymore.

Quote from: tarashy on December 06, 2014, 08:13:36 AM

Oh damn. Because the transaction consists of 12 parts, I expect a lenghts of 24 hours (by experiance)?!

While the size in bytes matters, the age and size of the inputs also matters.
See the formular for priority [1].

Quote from: tarashy on December 06, 2014, 08:13:36 AM

By the way: Nice chain exploit if would create thousands of those transactions at the same time... isnt it? Shocked

I wouldnt call it an exploit. As long as someone along the chain does not accept zero confirmation transactions the "attack" fails. And you should not accept transactions without confirmations for several reasons anyway.

[1] https://en.bitcoin.it/wiki/Transaction_fees#Technical_info

tarashy

newbie

Activity: 6

Merit: 0

Oh damn. Because the transaction consists of 12 parts, I expect a lenghts of 24 hours (by experiance)?!

By the way: Nice chain exploit if would create thousands of those transactions at the same time... isnt it? Shocked

shorena

copper member

Activity: 1498

Merit: 1528

No I dont escrow anymore.

Quote from: tarashy on December 06, 2014, 07:54:48 AM

Hm, to be honest... I doubt. The transaction concerned was initially started 2014-12-05 21:02:42 .......thats more then 15h now.

As you allready know this all depends on the TX [1] which is 2207 bytes in size but only pays 1000 Satoshi in fees. 20000 Satoshi would be reasonable. This will take a while.

[1] https://blockchain.info/de/tx/6024d009d6bb318bd8edb74957ad5d32aba8ca856c42ba6197ea138a7019a24a

twister

hero member

Activity: 672

Merit: 502

Yeah, you're right, it might take more because the initial transaction you posted above has a low miner's fee.

tarashy

newbie

Activity: 6

Merit: 0

Hm, to be honest... I doubt. The transaction concerned was initially started 2014-12-05 21:02:42 .......thats more then 15h now.

twister

hero member

Activity: 672

Merit: 502

Quote from: tarashy on December 06, 2014, 07:47:52 AM

Yes, I realized. But this transaction also has a non confirmed transaction and so on and so on and so on...up to the transaction I replied a second ago. How long may it take in worst case??

thanks

Yes, I see that now but considering all were sent with a Tx fee, they'll all get through soon. Not too sure but it may take up to an hour.

Although, I see now, this one is the culprit because the Tx fee used in this one is just 1k satoshi:

Quote from: tarashy on December 06, 2014, 07:41:44 AM

Am I right, that this is the beginning transaction thats blocks all the other transactions up to mine???

https://blockchain.info/tx/6024d009d6bb318bd8edb74957ad5d32aba8ca856c42ba6197ea138a7019a24a

tarashy

newbie

Activity: 6

Merit: 0

Yes, I realized. But this transaction also has a non confirmed transaction and so on and so on and so on...up to the transaction I replied a second ago. How long may it take in worst case??

thanks

twister

hero member

Activity: 672

Merit: 502

One of the sending address: 1CLLMQTGCtRTHvmDiJcXNbZry5n63tfsiQ
has an unconfirmed received transaction: dc776f9b788352dff862c6000a07ab6b202fae899b1cf457c0e65a84b076844f
when it goes through, the other will go through as well.

tarashy

newbie

Activity: 6

Merit: 0

Am I right, that this is the beginning transaction thats blocks all the other transactions up to mine???

https://blockchain.info/tx/6024d009d6bb318bd8edb74957ad5d32aba8ca856c42ba6197ea138a7019a24a

tarashy

newbie

Activity: 6

Merit: 0

Hey there,

for our shop we use the Blockchain API to generate (artificial) addresses for each customer (https://blockchain.info/de/api/api_receive). The customer himself sends then bitcoins to that generated address and finaly bitcoins are forwarded to our address.

One of our customers send his money to an generated address, this transaction already has 56 confirmations, but the the final forwading to our address gets no confirmations at all.

May you have a look and tell me whats wrong?

This is the address that should forward:
https://blockchain.info/address/19M6gi58egd8HTxpR6AmE7CYo5Eyq9aX9P

Topic: What the hell is wrong with this transaction... (Read 898 times)